1. Field of the Invention
The present invention relates to a power management method, and in particular, to a power management method using a G-sensor.
2. Description of Related Art
Along with the continuous development of the technology, handheld electronic devices such as a mobile phone, a personal digital assistant (PDA), and a note book have integrated a greater number of functions. Besides functions such as making calls, sending/receiving messages, and making notes, surfing the Internet and receiving/sending e-mails also have become basic functions of the handheld electronic devices in the current market. Multiple functions not only can facilitate people's life but also can provide entertainments, and thus the handheld electronic devices have become one of the most popular high-tech electronic products in the current market.
Generally, the handheld electronic devices are intended for use in the outdoors. Under such a circumstance where there is no external power supply available to the handheld electronic device, the only power source available to the handheld electronic device is the battery installed in the device. Accordingly, power management is one of the most important issues for the handheld electronic devices. How to control the handheld electronic devices to enter a power saving mode timely according to the users' usage condition for improving the efficiency of the battery and for extending the lifetime of the battery is crucial for the power management.
In terms of the power saving function of the handheld electronic device in the current market, the user has to set up a predetermined period of time on their own. The handheld electronic device enters the power saving mode only when the user has not operated the handheld electronic device for more than the predetermined time. The above-mentioned method controls the handheld electronic device to enter the power saving mode after the handheld electronic device operates in a normal operating mode for a period of time, so quite some power is wasted. Moreover, in addition to the above mentioned method for setting up the predetermined period of time, the user can also control the handheld electronic device to enter the power saving mode by selecting the power saving function from layered menus when the user wants to stop using the handheld electronic device. However, not only the manual control method wastes time, but the operating procedures are complicated, so that the user often feels troublesome and would rather not to use the power saving function. Therefore, the effect of power saving can not be carried out eventually.